The subject matter herein relates generally to terminal crimping devices using ultrasonic signals.
Terminals are typically crimped onto wires by means of a conventional crimping press having an anvil for supporting the electrical terminal and a ram that is movable toward and away from the anvil for crimping the terminal. In operation, a terminal is placed on the anvil, an end of a wire is inserted into the ferrule or barrel of the terminal, and the ram is caused to move toward the anvil to the limit of the stroke of the press, thereby crimping the terminal onto the wire. The ram is then retracted to its starting point.
As the crimping process continues some crimps may present quality problems such as missing wires or inadequate contact between the terminal and the wire. Consequently, quality inspections are needed to verify that continued quality crimps are formed. Current crimp quality systems inspect a sample of completed crimps or monitor the crimping process. However, the inspection of samples is time consuming and defects may still not be caught. Additionally, the current crimp monitoring process may not perform well for smaller wires.
New technologies in ultrasonic monitoring have been proposed for use in crimp quality monitoring. For example, U.S. Pat. No. 7,181,942 describes an ultrasonic device and method for measuring crimp connections by transmitting an acoustic signal from a transmitting transducer through the crimp connector to a receiving transducer and processing the signal to indicate the condition of the crimp.
Such ultrasonic monitoring systems are not without disadvantages. For instance, due to the shape of the crimp tooling required to deform the electrical terminal during the crimping process, the ultrasonic signal may be compromised or reduced. Reflected or echoed signals are essentially noise that may distort the signal received by the receiving transducer. The signal reflections may decrease the signal-to-noise ratio of the received signal and reduce the effectiveness of the analysis methods to detect crimp anomalies. Reduction in signal quality reduces the ability to detect quality errors which the ultrasonic monitoring system is designed to detect.
A need remains for a crimp quality monitoring system having improved signal reception at the receiving transducer.